German Application No. DE 101 08 196 A1, for example, describes a rotation rate sensor having Coriolis elements for measuring a rotation rate, which is located perpendicular on the substrate plane of the sensor. The sensor includes a first and a second Coriolis element, which are connected to each other via a spring, and are excited to vibrations parallel to a drive axis, a first and a second detection means detecting a deflection of the first and second Coriolis element parallel to a substrate plane, based on a Coriolis force acting upon the Coriolis elements, so that the difference of a first detection signal of the first detection means and a second detection signal of the second detection means is a function of the Coriolis force, and is consequently also a function of the rotation rate of the rotation rate sensor. The Coriolis elements, in this context, are movably connected via spring elements to a drive frame, and via the drive frame indirectly to the substrate. The spring elements are developed as U springs, which include two spiral springs running parallel to each other, which are firmly connected to each other via a head piece. By the bending of the spiral springs, a deflection is made possible of the drive frame and of the Coriolis element parallel to the substrate plane, as a result of the Coriolis force.
In addition, rotation rate sensors are known which are developed for the detection of a rotational rate extending parallel to the substrate plane. Such a rotation rate sensor is described in International Patent Publication No. WO 2005/043079 A2, for example. This rotation rate sensor has a similar functional principle, the Coriolis elements being driven to a drive vibration about a drive axis extending parallel to the main extension plane and perpendicular to the rate of rotation, and are then deflected to execute detection vibrations about a detection axis that is perpendicular to the substrate plane, based on the Coriolis forces.
In all the rotation rate sensors named, the drive vibration and the detection vibration are not completely separable from one another, so that, conditioned upon production tolerances, a cross feed comes about of the drive motion into the detection motion. This cross feed unfortunately produces a quadrature signal, whose amplitude is generally higher by a multiple than the actual measuring signal. The quadrature signal has to be suppressed, in a costly manner, by suitable measures during the design of the rotation rate sensor, for instance, by actively connected compensation electrodes, and during the electrical processing of the measuring signal. The main cause of the quadrature signal in micromechanical rotation rate sensors is that the spring elements used for suspending the Coriolis elements and drive means are not able to be processed ideally because of production tolerances. If these spring elements are stressed by forces (for instance, for producing the drive motion), they deflect themselves not only parallel to the attacking force but also orthogonally to this direction (for instance, parallel to the attacking direction), so that a cross feed of the drive motion into the detection motion takes place.